Rednet wireless redstone

rednet.open("top")
msg = "witherfarm"
side = "bottom"
reversed = true
active = false

function update()
	if reversed then
		rs.setOutput(side,not active)
	else
		rs.setOutput(side,active)
	end
end

update()

while true do
	event,id,message = os.pullEvent()
	if event == "rednet_message" then
		if message == msg.."on" then
			active = true
			update()
			print("Turned on.")
			rednet.broadcast(msg.." on.")
		elseif message == msg.."off" then
			active = false
			update()
			print("Turned off.")
			rednet.broadcast(msg.." off.")
		end
	end
end